[Age distribution of urinary tract infections (UTIs) and their severity grade in children (author's transl)].

Urinary tract infections in 339 children (77 boys and 262 girls) have been followed up. An excretory urography and a urethrocystography were done for all the children. The frequency of functional and anatomical abnormalities is given. The severity grade of UTI was determined according to the classification of Elo and Stenström. Almost all episodes of UTI among boys occurred during the first three years of life and were mostly severe. After the 3rd year of life the occurrence of UTI among the boys was sporadic. Among the girls the severe episodes dominates during the first three years of life, but after that the episodes tended to become milder in character becoming mostly asymptomatic. The peak of asymptomatic episodes among girls was at 10 years of age. After that age the number of episodes dropped abruptly. The classification used, based on the erythrocyte sedimentation rate (ESR) and on white blood cell count (WBC), has shown to be useful and makes it possible to differentiate between renal (pyelonephritic) episodes and the lower tract episodes.